Jim Boy is the name given to a young deaf and mute man who, after his parents were killed in a car accident, came to live with his grandmother in a small fishing village. Faced with indifferent or prejudiced locals who could not communicate with him, Jim Boy withdraws into his fantasies, especially that of repairing a shipwreck: 'His Boat', or 'Lady', which he would sail away in.
One day, Jim Boy happens on Sir Dennis Simpson, who is painting the shipwreck in search of inspiration after losing his family. Curious, Sir Dennis makes friends with Jim Boy and gives him a chance to paint, thus discovering Jim Boy's artistic talent. Sir Dennis continues to teach Jim Boy, selling his paintings as his own. When Sir Dennis dies, Jim Boy inherits all of his estate.